triple alpha resonances and possible link to the efimov

TRIPLE ALPHA RESONANCES AND POSSIBLE LINK TO THE EFIMOV
MECHANISM
Aurora Tumino, Università degli Studi di Enna “Kore” and LNS-INFN Catania, Italy
The basic condition for Efimov states is the existence of resonant two-body forces. A system of three
particles with resonant two-body interactions may form bound states, the so called Efimov trimers, even
when any two of the particles are unable to bind. Inspired by this idea we have analysed a set of data from
the 6Li+6Li3 reaction measured in a kinematically complete experiment at 3.1 MeV of beam energy,
with the characteristic that the 3 channel is fed by three 8Be states in the same event. A strong
enhancement in the - coincidence yield is experienced for these events. Evidence of three 8Be levels
within the same 3 event suggests that one  particle is exchanged between the other two. According to
quantum mechanics, this is a condition for Efimov states to occur and for which no observation exists yet
in nuclei. The hyperspherical formalism for the low-energy three-body problem has been applied to point
out the 3 particle correlation. Results from this study will be presented and discussed.
REFERENCES
[1] V. Efimov, Nature Physics 5, 533 (2009)